Mattress



FIG. 1 is a front perspective view of a mattress showing my new design;

FIG. 2 is a back perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof; and,

FIG. 9 is an enlarged detailed view taken from the encircled portion labeled 9 in FIG. 1 . 

CLAIM The ornamental design for a mattress, as shown and described. 